Please don't shoot the messenger. My left index finger recoiled a bit as it reached for the "T" on the keyboard. But it's true for this reason: Democrats are too earnest. They care too much. They're too smart. They know too much.

Whoever says, as California Sen. Kamala Harris did, "The American people are so much better than this" needs to get out more.

This isn't to recommend that primary candidates should be more like Trump, not that they could. But as a panel of candidates, they're missing a key element essential to voter interest. Not brilliant policies or the rote delivery of statistics but a clear and firm message as well as that other thing that Trump had in 2016 — "it."

We're used to saying "it girl," but boys have "it," too. And it isn't necessarily good. In fact, in men it's probably just a little bit bad. Bad enough to attract attention, to convey toughness, to seduce with dazzle or at least bedevil those around him. Love him or hate him — or just wish him away — Trump had the X-factor in spades and jokers.

Yes, yes, many Americans are surely ready for something different. But a Trump-like figure in the mix gives everyone a point of reference for contrasts and pivots.

As elder statesman and Democratic front-runner, Joe Biden was the obvious person to serve this role, but he's the opposite of the brooding, sarcastic, hunkering Trump from the 2016 campaign. Whereas Trump was the impudent scoundrel, dominating the field with the aloof self-confidence of an undefeated bully, Biden is the welcome guy at Walmart who wants to give everybody a great, big ol' hug.

Three years ago, Trump knew nothing, of course, but he made certain that viewers would not be bored. He hurled glib insults and tagged better men with insulting (but largely accurate) nicknames — and the crowds loved him. Today, Democratic contenders are so busy trying to demonstrate how un-Trump they are that they risk putting everyone to sleep. Be honest. Did you make it to the end of Thursday night's three-hour affair?

Also missing from the mix is a jester to the king. For Republicans in the 2016 cycle, it was South Carolina Sen. Lindsey Graham. Barely registering in the polls, Graham was so liberated by the impossibility of his nomination that he said only true things, including that Trump was a "race-baiting, xenophobic bigot" and "jackass." We watched the "kids table" GOP debates prior to the top guns just to find out what Graham would say. Miss that guy.

On Thursday, the zany Andrew Yang did offer some comic relief when he said, "I'm Asian, so I know a lot of doctors," thus supposedly making him an expert on health care. Otherwise he was plainly auditioning for a game show of his own. He offered to give $1,000 a month to 10 families for a year to show how his guaranteed minimum income policy would work. He also suggested giving all Americans $100 "democracy dollars" to spend on political causes.

Former HUD Secretary Julian Castro was laughable if not funny when he tried to make Biden look little. Fuming mad in that studied, must-show-passion way, Castro jabbed Biden for "forgetting" what he had just said, which wasn't true, but Castro was brandishing his narrative as the Latino, new-generation tough guy. It backfired.

Honorable mention goes to former Texas Rep. Beto O'Rourke, who broke out with his strongest stand yet on gun control: "Hell, yes, we're going to take your AR-15, your AK-47," he intoned, sounding very fierce. Also noteworthy, Biden earned a new voter bloc among the incarcerated population when he said, "Nobody should be in jail for a nonviolent crime."

In sum: Vermont Sen. Bernie Sanders was very Bernie. Massachusetts Sen. Elizabeth Warren was A-plus perfect. Harris was prosecutorial. New Jersey Sen. Cory Booker was bookishly faithful to his narrative. Biden was grown-up. Minnesota Sen. Amy Klobuchar was emphatically moderate. And South Bend Mayor Pete Buttigieg, the Mr. Rogers of American politics, would make everything tidy.

Entertainment value, obviously, should play no part in a voter's calculation. But as all public speakers know, audiences don't remember what you said; they remember how you made them feel. Trump made people feel excited, if for all the wrong reasons. This crew? Serotonin on the rocks without a twist.